-/*
- Copyright (C) 2006 Hans Fugal & Paul Davis
+/*
+ Copyright (C) 2006 Paul Davis
+ Author: Hans Fugal
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: /local/undo/libs/pbd3/pbd/undo.h 132 2006-06-29T18:45:16.609763Z fugalh $
*/
#ifndef __lib_pbd_memento_command_h__
#define __lib_pbd_memento_command_h__
-#include <pbd/command.h>
+#include <iostream>
+
+#include "pbd/libpbd_visibility.h"
+#include "pbd/command.h"
+#include "pbd/stacktrace.h"
+#include "pbd/xml++.h"
+#include "pbd/demangle.h"
+
#include <sigc++/slot.h>
+#include <typeinfo>
-/** This command class is initialized with before and after mementos
- * (from Stateful::get_state()), so undo becomes restoring the before
- * memento, and redo is restoring the after memento.
+/** A class that can return a Stateful object which is the subject of a MementoCommand.
+ *
+ * The existence of this class means that the undo record can refer to objects which
+ * don't exist in the session file. Currently this is used for
+ *
+ * 1. MIDI automation; when MIDI automation is edited, undo records are
+ * written for the AutomationList being changed. However this AutomationList
+ * is a temporary structure, built by a MidiModel, which doesn't get written
+ * to the session file. Hence we need to be able to go from a MidiSource and
+ * Parameter to an AutomationList. This Binder mechanism allows this through
+ * MidiAutomationListBinder; the undo record stores the source and parameter,
+ * and these are bound to an AutomationList by the Binder.
+ *
+ * 2. Crossfades; unlike regions, these are completely removed from a session
+ * when they are deleted. This means that the undo record can contain
+ * references to non-existant crossfades. To get around this, CrossfadeBinder
+ * can do `just-in-time' binding from the crossfade ID.
*/
template <class obj_T>
-class MementoCommand : public Command
+class LIBPBD_TEMPLATE_API MementoCommandBinder : public PBD::Destructible
{
- public:
- MementoCommand(obj_T &obj,
- XMLNode &before,
- XMLNode &after
- )
- : obj(obj), before(before), after(after) {}
- void operator() () { obj.set_state(after); }
- void undo() { obj.set_state(before); }
- virtual XMLNode &get_state()
- {
- XMLNode *node = new XMLNode("MementoCommand");
- // obj.id
- // key is "MementoCommand" or something
- // before and after mementos
- return *node;
- }
- // TODO does this need a copy constructor?
- protected:
- obj_T &obj;
- XMLNode &before, &after;
+public:
+ /** @return Stateful object to operate on */
+ virtual obj_T* get () const = 0;
+
+ /** @return Name of our type */
+ virtual std::string type_name () const {
+ return PBD::demangled_name (*get ());
+ }
+
+ /** Add our own state to an XMLNode */
+ virtual void add_state (XMLNode *) = 0;
};
+/** A simple MementoCommandBinder which binds directly to an object */
template <class obj_T>
-class MementoUndoCommand : public Command
+class LIBPBD_TEMPLATE_API SimpleMementoCommandBinder : public MementoCommandBinder<obj_T>
{
public:
- MementoUndoCommand(obj_T &obj,
- XMLNode &before)
- : obj(obj), before(before) {}
- void operator() () { /* noop */ }
- void undo() { obj.set_state(before); }
- virtual XMLNode &get_state()
- {
- XMLNode *node = new XMLNode("MementoUndoCommand"); // XXX
- // obj.id
- // key is "MementoCommand" or something
- // before and after mementos
- return *node;
- }
-protected:
- obj_T &obj;
- XMLNode &before;
+ SimpleMementoCommandBinder (obj_T& o)
+ : _object (o)
+ {
+ _object.Destroyed.connect_same_thread (_object_death_connection, boost::bind (&SimpleMementoCommandBinder::object_died, this));
+ }
+
+ obj_T* get () const {
+ return &_object;
+ }
+
+ void add_state (XMLNode* node) {
+ node->set_property ("obj_id", _object.id().to_s());
+ }
+
+ void object_died () {
+ /* The object we are binding died, so drop references to ourselves */
+ this->drop_references ();
+ }
+
+private:
+ obj_T& _object;
+ PBD::ScopedConnection _object_death_connection;
};
+/** This command class is initialized with before and after mementos
+ * (from Stateful::get_state()), so undo becomes restoring the before
+ * memento, and redo is restoring the after memento.
+ */
template <class obj_T>
-class MementoRedoCommand : public Command
+class LIBPBD_TEMPLATE_API MementoCommand : public Command
{
public:
- MementoRedoCommand(obj_T &obj,
- XMLNode &after)
- : obj(obj), after(after) {}
- void operator() () { obj.set_state(after); }
- void undo() { /* noop */ }
- virtual XMLNode &get_state()
- {
- XMLNode *node = new XMLNode("MementoUndoCommand");
- // obj.id
- // key is "MementoCommand" or something
- // before and after mementos
- return *node;
- }
+ MementoCommand (obj_T& a_object, XMLNode* a_before, XMLNode* a_after)
+ : _binder (new SimpleMementoCommandBinder<obj_T> (a_object)), before (a_before), after (a_after)
+ {
+ /* The binder's object died, so we must die */
+ _binder->DropReferences.connect_same_thread (_binder_death_connection, boost::bind (&MementoCommand::binder_dying, this));
+ }
+
+ MementoCommand (MementoCommandBinder<obj_T>* b, XMLNode* a_before, XMLNode* a_after)
+ : _binder (b), before (a_before), after (a_after)
+ {
+ /* The binder's object died, so we must die */
+ _binder->DropReferences.connect_same_thread (_binder_death_connection, boost::bind (&MementoCommand::binder_dying, this));
+ }
+
+ ~MementoCommand () {
+ drop_references ();
+ delete before;
+ delete after;
+ delete _binder;
+ }
+
+ void binder_dying () {
+ delete this;
+ }
+
+ void operator() () {
+ if (after) {
+ _binder->get()->set_state(*after, Stateful::current_state_version);
+ }
+ }
+
+ void undo() {
+ if (before) {
+ _binder->get()->set_state(*before, Stateful::current_state_version);
+ }
+ }
+
+ virtual XMLNode &get_state() {
+ std::string name;
+ if (before && after) {
+ name = "MementoCommand";
+ } else if (before) {
+ name = "MementoUndoCommand";
+ } else {
+ name = "MementoRedoCommand";
+ }
+
+ XMLNode* node = new XMLNode(name);
+ _binder->add_state (node);
+
+ node->set_property ("type_name", _binder->type_name ());
+
+ if (before) {
+ node->add_child_copy(*before);
+ }
+
+ if (after) {
+ node->add_child_copy(*after);
+ }
+
+ return *node;
+ }
+
protected:
- obj_T &obj;
- XMLNode &after;
+ MementoCommandBinder<obj_T>* _binder;
+ XMLNode* before;
+ XMLNode* after;
+ PBD::ScopedConnection _binder_death_connection;
};
#endif // __lib_pbd_memento_h__
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